Original isa120/130 repairs

[sr1200]

Wanted to see if anyone had any experience with these. Studio in my area has a pair of these racked that are in disrepair. Switches seem very dirty and the sound is just as dirty.  I dont think its ever been recapped (ps 121h or the individual units). He said the little meter displays are not working properly either.  Cant imagine they would be easy to find.

 

[fazer]

Caps could be causing all the problems your describing between leakage and capacitor values reducing and high end ESR

 

[sr1200]

Kind of what i figured.  first things i would go after would be the electrolytics... do you think id need to go after the ceramic and film caps as well?

 

[fazer]

Kind of what i figured.  first things i would go after would be the electrolytics... do you think id need to go after the ceramic and film caps as well?

I would think just electrolytics,  I had one focusrite that had a problem with a level pot.  Don’t get heavy handed when tighting pots .  You can break the pot from the track by pulling the center with the not to far forward.  Had that problem on a 430 years ago.  Also recommend a Hakka desolder gun or similar vac solder station.  There usually are a lot of 100uf bypass caps on a 2 sided board and it make it easier to remove without destroying the board.

 

[sr1200]

Thanks for the heads up. I have a pretty decent desoldering pump which i dont know how i got by without.  The owner is checking if he has a schematic for the units